UNIVERSITY     OF    CALIFORNIA    PUBLICATIONS 

COLLEGE    OF    AGRICULTURE 
AGRICULTURAL    EXPERIMENT    STATION 

BERKELEY,     CALIFORNIA 


POTASH  FROM  TULE 

AND    THE 

FERTILIZER  VALUE  OF  CERTAIN 
MARSH  PLANTS 


BY 

P.  L.   HIBBARD 


BULLETIN  No.  288 

November,   1917 


381)14 


CALIFORNIA  STATE  PRINTING  OFFICE 

SACRAMENTO 

19  17 


Benjamin  Ide  Wheeler,  President  of  the  University. 

EXPERIMENT  STATION  STAFF 

HEADS   OF   DIVISIONS 

Thomas  Foesyth  Hunt,  Director. 

Edward  J.  Wickson,  Horticulture  (Emeritus). 

Herbert  J.  Webber,  Director  Citrus  Experiment  Station ;  Plant  Breeding. 

Hubert  E.  Van  Norman,  Vice-Director ;  Dairy  Management. 

William  A.  Setchell,  Botany. 

Myer  E.  Jaffa,  Nutrition. 

♦Robert  H.  Loughridge,  Soil  Chemistry  and  Physics   (Emeritus), 

Charles  W.  Woodworth,  Entomology. 

Ralph  E.  Smith,  Plant  Pathology. 

J.  Eliot  Coit,  Citriculture. 

John  W.  Gilmore,  Agronomy. 

Charles  F.  Shaw,  Soil  Technology. 

John  W.  Gregg,  Landscape  Gardening  and  Floriculture. 

Frederic  T.  Bioletti,  Viticulture  and  Enology. 

Warren  T.  Clarke,  Agricultural  Extension. 

John  S.  Burd,  Agricultural  Chemistry. 

Charles  B.  Lipman,  Soil  Chemistry  and  Bacteriology. 

Clarence  M.  Haring,  Veterinary  Science  and  Bacteriology. 

Ernest  B.  Babcock,  Genetics. 

Gordon  H.  True,  Animal  Husbandry. 

James  T.  Barrett,  Plant  Pathology. 

Fritz  W.  Woll,  Animal  Nutrition. 

Walter  Mulford,  Forestry. 

W.  P.  Kelley,  Agricultural  Chemistry. 

H.  J.  Quayle,  Entomology. 

D.  T.  Mason,  Forestry. 

J.  B.  Davidson,  Agricultural  Engineering. 

Elwood  Mead,  Rural  Institutions. 

H.  S.  Reed,  Plant  Physiology. 

W.  L.  Howard,  Pomology. 

fFRANK  Adams,  Irrigation  Practice. 

C.  L.  Roadhouse,  Dairy  Industry. 

O.  J.  Kern,  Agricultural  Education. 

John  E.  Dougherty,  Poultry  Husbandry. 

S.  S.  Rogers,  Olericulture. 

David  N.  Morgan,  Assistant  to  the  Director. 

Mrs.  D.  L.  Bunnell,  Librarian. 

DIVISION  OF  AGRICULTURAL  CHEMISTRY. 

John  S.  Burd  P.  L.  Hibbard 

Dennis  R.  Hoagland  Arthur  W.  Christie 

Guy  R.   Stewart  J.  C.  Martin 


*Died  July  1,   1917. 

•f-In  cooperation  with  office  of  Public  Roads  and  Rural  Engineering,  U.  S.  Depart- 
ment of  Agriculture. 


POTASH   FROM  TULE  AND  THE  FERTILIZER  VALUE  OF 

CERTAIN  MARSH  PLANTS. 

By    P.    L.    HlBBARD.* 

A  brief  study  indicates  that  100  to  200  pounds  of  potash  to  the  acre, 
worth  at  present  prices,  $15.00  to  $30.00,  may  be  obtained  from  a  heavy 
growth  of  tule,  at  a  cost  of  perhaps  $5.00  to  $10.00  per  acre.  Though 
this  study  is  not  extensive,  the  facts  developed  seem  of  sufficient  import- 
ance to  warrant  publication  without  further  delay. 

Tule  land  usually  has  great  agricultural  value  after  it  has  been 
reclaimed  from  its  marshy  condition.  It  is  thought  that  much  of  the 
expense  of  reclamation  may  be  defrayed  by  the  value  of  the  potash 
contained  in  the  marsh  vegetation.  At  the  present  time  any  source 
from  which  potash  may  be  obtained  at  reasonable  cost  is  of  much 
interest.  Whether  a  profitable  industry  of  extracting  potash  from  tule 
can  be  developed  remains  to  be  proved  by  actual  experience  on  a  large 
scale.  The  object  of  this  paper  is  to  bring  the  matter  to  the  attention 
of  those  whom  it  may  interest,  with  the  hope  that  commercial  enterprise 
will  demonstrate  its  possibilities. 

Description,  Location  and  Habits  of  Tule. 

The  tule  plant  (Scirpus  lacustris,  var.  occidentalis)  is  a  member  of 
the  botanical  family  of  sedges  frequently  seen  growing  in  the  edges  of 
ponds  or  in  marshy  places.  It  is  closely  related  to  the  common  bulrush 
of  the  eastern  portion  of  the  United  States.  The  plant  sends  up  an 
annual  growth  of  round,  tapering  dark  green  stems,  four  to  ten  feet 
high  and  one-fourth  to  one  inch  thick  at  the  base,  tapering  to  a  point 
at  the  top  which  often  bears  a  small  bunch  of  flowers  or  seeds.  With  the 
tule  are  commonly  found  other  water-loving  plants,  such  as  the  sedges, 
grass-like  plants  of  smaller  size  having  a  triangular  stem;  and  cattails, 
often  called  flags,  which  have  long  flat  leaves  surrounding  the  base  of 
a  tall  round  stalk  at  the  top  of  which  is  a  brown  cylindrical  mass  of 
seed  commonly  known  as  cattail.  All  these  and  some  others  grow  in 
quiet,  shallow  water.  Where  the  water  never  dries  up  they  are  largest. 
After  the  water  disappears  the  tule  ceases  to  grow,  but  many  of  the 
sedges  and  cattails  continue  to  flourish  as  long  as  the  ground  is  moist. 
All  produce  an  annual  growth  which  dies  during  the  winter. 

The  area  of  tule  land  in  California  is  estimated  at  500,000  acres. 
Much  of  this  has  been  reclaimed  but  it  is  thought  that  there  still  remains 
in  the  delta  region  of  the  San  Joaquin  and  Sacramento  rivers  alone 
50,000  acres  largely  covered  with  tule.  On  much  of  this  ground  the 
growth  is  too  sparse  or  too  inaccessible  to  be  of  much  value.  In  many 
other  parts  of  the  state  are  considerable  areas  of  tule  land.  In  over- 
flowed regions  the  tule  is  found  over  broad  areas,  but  is  most  luxuriant 
along  the  edges  of  sloughs  and  channels  in  strips  ten  to  twenty  feet 
wide,  where  it  always  has  a  good  supply  of  water.  It  grows  in  both 
fresh  and  brackish,  but  not  in  salt,  water. 

The  weight  of  tule  on  an  acre  is  exceedingly  variable.  Measurements 
of  small  areas  in  a  number  of  places  indicate  that  the  green  plants  on 
one  square  foot  weigh  one-half  to  over  one  pound  which  would  make 
ten  to  twenty  tons  per  acre.  In  drying  three-fourths  of  the  weight  is 
lost.  The  following  Table  I  indicates  the  source  and  condition  of  the 
plants  studied. 

♦Note. — Grateful   acknowledgment   is  made   to   Professor  J.    S.    Burd  for  valuable 
counsel  and  suggestions. 


188 


UNIVERSITY   OF    CALIFORNIA EXPERIMENT   STATION. 


TABLE   I. 
Location,    Condition,    Etc.,    of    Plants   Analyzed. 


53 
o 


Name 


Condition  of  plants 


Locality 


a  » 

CO    ^ 

bo  a 

CO 


H 

"     O 


B 


CD   CD 


o 

IS 

5' 


1 

2 

5 

6 

11 

15 

17 

18 

20 

21 

23 

27 

30 

28 

24 

25 

26 

4 

9 

3 

10 

13 

7 

12 

14 

22 

8 

16 
29 


Tule 

Tule 

Tule 

Tule 

Tule 

Tule 

Tule 

Tule 

Tule _ 

Tule 

Tule 

Tule  _ 

Tule  .. 

Tule  and  sedge 

)  Tule,      sedge,      cattail 
[     and  weeds 


Tule 

Tule 

Sedge   

Sedge   

Sedge   

Cattail 

Cattail 

Cattail 

Cattail 

Cattail 

Cattail  _._. 
Fire  weeds 


Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  and  1/10  dead 

Fresh  

Fresh  and  1/10  dead 

1/3  dead  — 

Fresh  

1/3  dead  

r 

1/3  dead •{ 

I 

Dead 

Dead 

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Dead 

Dead 

Fresh  


Stockton  

Alvarado  

Mallard   

Mallard   

Benicia  

Suisun 

Newman    

Newman    

Middle  River  ... 
Middle  River  __. 
West  Pittsburg. 

Lisbon  

Lisbon   

Lisbon  

Lisbon   

Lisbon   

Lisbon   

Alvarado    

Mallard   

Alvarado    

Benicia  

Suisun 

Mallard   

Benicia  

Suisun 

Bay  Point 

Mallard   

Suisun 

Lisbon   


6 
2-10 
0-  6 
0-  6 
2-  6 
2-  6 


2-12 

12-24 

0-  6 

None 

2-12 

None 

None 

None 

None 

2-10 

0-  6 

0-  2 

2-  6 

2-  6 

0-  6 

2-  6 

2-  6 

2-  4 

0-  6 

2-  6 

None 


5-6 

4-8 

10 

8 

4-7 

5-7 

4-6 

3-4 

4-8 

4-8 

5-8 

5-7 

5.8 

5-7 

4-6 

4-6 

4-6 

4-8 

6 

2-3 

4 

4-6 

5 

5 

5 

3-5 

5 

5 

3-5 


25 

20 

1 

1 

6 

3 

20 

20 

15 

15 

15 

20 

10 

20 

25 

25 

25 

20 

5 

10 

3 

3 

1 

2 

3 

10 

1 

2 

15 


May  15 
May  28 
June  11 
June  11 
June  11 
June  11 
June  15 
June  15 
July  13 
July  13 
July  20 
July  26 
July  26 
July  26 
July  26 
July  26 
July  26 
May  28 
June  11 
May  28 
June  11 
June  11 
June  11 
June  11 
June  11 
July  20 
June  11 
June  11 
July  26 


Composition  of  Various  Plants. 

The  composition  of  the  tule  plants  varies  greatly,  as  is  indicated  by 
Table  II  following.  A  few  analyses  indicate  that  the  young  plants 
contain  the  highest  proportion  of  potash,  though  the  old  plants  may 
give  a  greater  yield  of  potash  per  acre  on  account  of  the  larger  tonnage. 
Reasoning  by  analogy  from  our  definite  knowledge  of  other  plants  we 
should  reach  the  same  conclusion.  This  study  is  not  yet  sufficiently 
extensive  to  prove  the  theory  in  regard  to  tule.  However,  it  is  definitely 
shown  that  dead  plants  or  those  which  have  been  leached  by  water 
retain  only  a  small  amount  of  potash. 

Effect  of  Leaching*. 

The  loss  of  potash  by  leaching  is  shown  by  the  following  experiment : 
A  bunch  of  the  stems  was  soaked  in  water  overnight.  The  water  was 
poured  off  and  the  stems  again  covered  with  fresh  water  to  stand 
another  day;  this  was  repeated  once  more.  Finally  potash  was  deter- 
mined in  the  different  extracts.  Of  the  total  potash  present  before 
soaking  15  per  cent  remained  in  the  stems,  58  per  cent  was  in  the  first 
leaching,  18  per  cent  in  the  second  leaching,  and  9  per  cent  in  the  third 
leaching.  This  indicates  that  a  large  portion  of  the  potash  is  not 
organically  combined  in  the  plant,  and  shows  that  to  obtain  much 
potash  the  plants  must  be  harvested  before  rain  washes  out  the  valuable 
salts. 


POTASH    FROM    TULE. 


189 


TABLE    II. 
Percentage — Composition   of   Plants. 


o 


Name 


Condition  of  plants 


Fresh  material 


3 

p 

ct- 


W 

o 


Water-free  material 


o 

fftj 


is 

O 


o 


> 


W 

to 

o 


1 

2 

5 

6 

11 

15 

17 

18 

20 

21 

23 

27 

30 

28 

24 

25 

26 

4 

9 

3 

10 

13 

7 

12 

14 

22 

8 

16 

29 


Tule    • 

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule    

Tule   and   sedge 

]  Tule,  sedge,  cattail 
\-     and  weeds   

J 

Tule    

Tule    

Sedge   

Sedge   

Sedge   

Cattail    

Cattail    

Cattail 

Cattail    

Cattail    

Cattail    

Fire  weeds  


Fresh  

Fresh  

Fresh   

Fresh  

Fresh  

Fresh  

Fresh   

Fresh 

Fresh   and   1/10  dead 

Fresh   

Fresh    and   1/10   dead 

1/3  dead  

Fresh   

1/3   dead   

1/3  dead  J 

Dead  

Dead  

Fresh __. 

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Fresh  

Dead  

Dead  

Nearly  fresh   


76.5 

3.1 

0.77 

1.86 

0.71 

3.3 

12.9 

75.0 
75  est.* 

3.1 
3.7 

0.42 
1.23 

1.7 
4.9 

12.2 
14.8 

1.28 

0.51 

75  est.* 

3.3 

0.95 

1.80 

0.62 

3.8 

13.2 

75  est.* 
75  est.* 

2.8 
3.0 

0.80 
0.75 

3.2 

2.9 

11.3 
12.1 

1.19 

0.41 

75  est.* 

2.6 

0.75 

0.91 

2.9 

10.6 

75  est.* 
75.8 

2.7 
2.4 

0.80 
0.26 

3.2 
1.1 

10.7 
10.0 

1.43 

0.48 

68.4 

2.2 

0.57 

1.17 

1.8 

6.8 

77.5 

2.7 

0.48 

1.25 

2.2 

11.9 

58.3 

3.9 

0.92 

0.75 

2.2 

9.4 

75  est.* 

52.0 

54.4 

4.8 
4.7 

0.39 
1.01 
1.00 

2.3 
2.1 

2.2 

16.5 
10.1 
10.3 

54.4 
60.0 

4.3 

3.2 

1.05 
0.76 

2.3 

1.9 

9.4 
8.1 

0.70 

0.40 

63.1 
50  est.* 

3.7 
6.6 

0.99 
0.05 

2.7 
0.1 

10.1 
13.3 

0.78 

0.15 

85.9 

1.8 

0.52 

1.86 

0.54 

3.9 

13.0 

85  est.* 

3.0 

0.45 

2.02 

0.51 

3.0 

19.8 

85  est.* 

2.3 

0.63 

1.95 

0.51 

4.2 

15.6 

75  est.* 

2.9 

0.87 

1.55 

0.52 

3.5 

11.8 

75  est.* 

3.6 

0.57 

2.3 

14.5 

75  est.* 
72.2 

2.8 
2.0 

0.88 
0.31 

3.5 

1.1 

11.0 
7.0 

0.95 

0.48 

50  est.* 

3.8 

0.60 

0.94 

0.52 

1.2 

7.5 

50  est.* 

3.1 

0.15 

0.53 

0.32 

0.3 

6.2 

62.5 

2.1 

0.64 

0.71 

0.31 

1.7 

5.5 

25.4 
13.8 
32.7 
28.8 
28.3 
23.2 
26.6 
30.0 
11.0 
26.5 
18.3 
23.4 
14.5 
20.8 
21.3 
24.4 
23.4 
25.8 

0.8 
30.0 
15.2 
27.0 
30.0 
16.5 
31.7 
14.9 
16.0 

4.8 
30.9 


*Est.  indicates  that  amount  of  water  was  estimated,  not  actually  determined. 

The  amount  of  potash  in  tule  ash  is  also  quite  variable,  as  will  be 
seen  by  a  study  of  Table  II.  It  seems  probable  that  plants  growing 
in  a  scanty  supply  of  water  or  in  saline  water  carry  a  larger  proportion 
of  potash  in  the  ash. 

Composition  of  Tule  Ash. 

This  has  been  only  slightly  studied.  A  proximate  analysis  of  the  ash 
is  given  in  Table  III.  From  this  it  seems  that  the  potash  in  the  tule  is 
largely  present  in  mineral  condition  and  not  organically  combined  as  in 
most  land  plants.  In  this  respect  it  resembles  the  kelps  of  the  ocean. 
This  ash  was  obtained  by  burning  several  pounds  of  sample  No.  2  on  an 
iron  plate  in  open  air.  It  was  separated  by  leaching  with  water  into 
the  insoluble  and  the  water-soluble  portions. 

TABLE    III. 

The  total  ash  contained : 

Unburnt  carbon 14.4  per  cent 

"Water  insoluble  mineral  matter 40.3  per  cent 

Water  soluble  salts 45.3  per  cent 

100.00  per  cent 

The  water  soluble  salts  consisted  of: 

Na»0 8.0  per  cent 

K26 16.8  per  cent 

CI 14.4  per  cent 

S03     4.7  per  cent 

C02 1-4  per  cent 

45.3  per  cent 

The  water-insoluble  mineral  matter  consisted  of  sand,  clay,  iron  oxid, 
etc.,  with  a  little  lime  and  magnesia. 


190 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION. 


Harvesting  the  Tule. 

As  above  indicated  the  tule  should  be  harvested  before  the  leaching 
action  of  rain  begins,  probably  best  during  September  or  sooner. 

The  crop  may  be  cut  with  an  ordinary  mowing  machine  if  the  ground 
is  dry  enough  to  bear  a  team.  After  it  has  dried  somewhat  it  may  be 
raked  into  piles  and  carried  to  a  smooth  spot  of  hard  ground  from 
which  the  ashes  may  be  easily  shoveled  up  after  the  tule  is  burned.  It 
will  not  be  necessary  to  wait  till  it  is  very  dry  to  burn  it  as  after  the 
fire  is  once  started  it  will  furnish  heat  enough  to  keep  burning  compara- 
tively green  material.  This  is  desirable  in  order  to  avoid  a  very  high 
temperature  which  would  be  liable  to  cause  loss  of  potash. 

The  quantity  of  dry  material  and  amount  of  potash  per  acre  with 
other  conditions  are  indicated  in  Table. IY. 

The  rankest  growth  of  tule  is  found  along  the  edges  of  streams  and 
swamps  where  there  is  always  more  or  less  water,  so  that  it  will  never 
be  possible  to  harvest  it  by  means  of  an  ordinary  mowing  machine.  It 
is  not  probable  that  hand-cutting  will  pay.  A  machine  something  like 
a  grain  harvester  mounted  on  a  scow  would  probably  be  able  to  cut  the 
tule  cheaply  (and  convey  it  to  a  spot  where  it  could  be  dried  and 
burned).  The  whole  operation  must  be  well  planned  and  worked  out  so 
as  to  handle  the  crop  very  inexpensively  because  the  value  of  the 
product  is  not  great  enough  to  bear  any  costly  method  of  harvesting. 

TABLE   IV. 
Yield  of  Air-Dry   Material   and   Potash. 


o 


Name 


Location 


Per  cent  potash 


In 

air-dry 

material 


In  ash 


Yield  per  acre  (lbs.) 


Air-dry 
material 


Potash 


Depth 
of  water 

on 
ground 


20 
21 
23 
27 
28 
22 
24 
25 
26 


Tule    

Tule  and  10%  cattail 

Tule    

Tule    _. 

Tule  and  sedge 

Cattail 

]  Tule,      sedge,      cattail, 

j-     weeds  

J 


Middle   River   

Middle  River 

West  Pittsburg  __ 

Lisbon 

Lisbon 

Bay  Point 

Lisbon 

Lisbon 

Lisbon 


1.0 

11.0 

18,000 

171 

1.6 

26.5 

12,000 

212 

2.0 

18.3 

13,000 

254 

2.0 

23.4 

6,000 

102 

1.9 

20.8 

7,000 

134 

1.0 

14.9 

15,000 

157 

2.0 

21.3 

4,000 

87 

2.1 

24.4 

4,000 

87 

1.7 

23.4 

5,000 

86 

1  ft. 

2  ft. 

h  ft. 

None 
None 
i  ft. 

None 
None 
None 


Extraction  of  Potash  From  the  Ash. 

It  is  shown  above  that  much  of  the  potash  may  be  extracted  from  tule 
by  leaching,  but  in  general  it  will  be  simpler  to  burn  it*  first.  The  dry 
hay  burns  easily.  All  that  is  necessary  is  to  get  it  onto  ground  where 
the  ash  can  be  easily  recovered,  and  to  avoid  high  temperatures  which 
would  cause  loss  of  potash.  After  burning,  it  will  probably  be  desirable 
to  moisten  the  ash  which  is  very  light,  in  order  to  prevent  loss  by 
blowing.  The  ash  may  be  used  directly  as  a  potash  fertilizer  or  it  may 
be  leached  with  water  to  make  high-grade  potash  salts.  If  the  water  is 
made  to  percolate  slowly  through  the  ash,  the  first  runnings,  in  volume 
about  equal  to  the  volume  of  the  ash,  will  contain  most  of  the  potash. 
Fresh  water  will  then  extract  more  of  the  potash.  The  weak  extract  thus 
obtained  should  be  used  instead  of  fresh  water  to  extract  new  ash.    In 


POTASH   FROM    TULE.  191 

this  way  most  of  the  potash  will  be  obtained  with  a  minimum  amount  of 
water  which  must  be  evaporated  to  obtain  the  potash  salts.  The  first 
crystallization  of  salts  from  the  leachings  is  largely  composed  of  potas- 
sium chloride  and  surlate,  containing  nearly  50  per  cent  K20.  Further 
evaporation  and  crystallization  yields  a  product  containing  less  potash. 
The  process  should  be  similar  to  that  used  in  obtaining  potash  from 
wood  ashes. 

In  order  to  manufacture  high-grade  potash  salts  from  tule  a  consider- 
able plant  and  experienced  management  will  probably  be  required, 
therefore  such  manufacture  is  not  here  advocated.  The  present  object 
is  rather  to  indicate  the  possibility  of  obtaining  at  small  expense,  by 
inexperienced  persons,  tule  ash  containing  potash  in  a  form  which  may 
be  used  as  a  fertilizer  and  in  some  measure  help  to  pay  the  cost  of 
recovery  of  the  land. 

Comparison  of  Tule  With  Other  Sources  of  Potash. 

Crude  tule  ash  contains  7  to  15  per  cent  K20,  which  is  more  than  most 
wood  ashes  contain.  The  tule  ash  here  meant  is  the  crude  ash  containing 
much  carbon  and  soil,  not  the  pure  ash  given  in  Table  II.  The  percent- 
age of  crude  ash  is  considerably  greater  than  of  the  pure  ash.  Unlike 
wood  ashes,  in  which  most  of  the  potash  is  present  as  carbonate  there  is 
but  little  of  this  form  in  tule  ash.  In  this  particular  it  is  quite  similar 
to  kelp  ash,  which  contains  most  of  its  potash  as  chloride.  In  other 
respects  it  is  not  similar  to  kelp  ash. 

The  available  potash  in  tule  ash  is  similar  to  that  of  carnallite  from 
the  Stassfurt  mines,  which  contains  about  10  per  cent  of  K20,  chiefly  in 
the  form  of  chloride.  Part  of  the  tule  potash  is  in  the  form  of  sulfate. 
The  tule  ash  should  be  preferable  to  carnallite  or  kainit  as  a  fertilizer 
because  it  contains  less  of  the  other  undesirable  chlorides.  Like  the 
other  sources  of  potash  above  mentioned,  tule  ash  is  not  suitable  for 
mixing  with  other  materials  to  make  high-grade  fertilizers  because  the 
large  amount  of  inert  material  in  it  would  lower  the  grade  of  the  com- 
plete fertilizer.  The  high-grade  potash  salts  obtained  by  extracting  tule 
ash  would  be  suitable  for  high-grade  fertilizers. 

Fertilizer  Value  of  Tule. 

Reference  to  Table  V  will  show  that  tule  has  considerable  value  as  a 
source  of  plant  food.  If  plowed  under  it  will  probably  decay  readily, 
thus  liberating  its  plant  food  and  at  the  same  time  furnishing  valuable 
humus  which  is  commonly  needed  in  California  soils.  As  a  source  of 
plant  food  the  fresh  tule  compares  well  with  barnyard  manure  and  other 
waste  materials,  such  as  straw  or  leaves.  Like  these  it  is  not  valuable 
enough  to  bear  high  cost  of  transportation,  so  that  it  must  be  used 
near  where  it  grows.  However,  tule  land  itself  is  not  likely  to  be 
benefited  by  the  addition  of  tule  as  a  fertilizer. 


192 


UNIVERSITY    OP    CALIFORNIA EXPERIMENT   STATION. 


TABLE   V. 

Plant   Food   in   Various  Species  of   Marsh   Growth. 

(Pounds  in  one  ton  of  fresh  materiaj.) 


No. 


1 

5 

6 

15 

9 

7 

22 

16 

3 

10 

13 


Name 


Tule   

Tule   

Tule  

Tule  

Tule,  dead  _. 

Cattail  

Cattail  

Cattail,  dead 

Sedge    

Sedge    

Sedge    _. 


Nitrogen 

P2O5 

9.2 

3.6 

6.4 

2.6 

9.0 

3.1 

6.0 

2.0 

7.6 

1.5 

7.8 

2.6 

5.3 

2.8 

5.3 

3.2 

5.2 

1.5 

6.0 

1.4 

5.8 

1.4 

K20 


15.4 
24.6 
19.0 
14.5 

1.0 
17.5 

6.2 

3.0 
10.6 

9.0 
12.6 


As  a  fertilizer  material  the  tule  has  some  resemblance  to  the  potash- 
bearing  kelps  of  the  Pacific  Coast. 

Fresh  kelp  (Macrocystis  pyrifera),  according  to  Burd*,  contains  in 

1  ton  about  4  pounds  of  nitrogen,  2  pounds  phosphoric  acid  and 
36  pounds  of  potash.    Fresh  tule  contains  about  6  pounds  of  nitrogen, 

2  pounds  phosphoric  acid,  12  pounds  of  potash.  Barnyard  manure 
contains  about  2  pounds  of  nitrogen,  2  pounds  phosphoric  acid  and 
4  pounds  of  potash  per  ton.  All  of  these  figures  vary  considerably  with 
season,  locality  and  treatment  of  the  particular  material.  The  tule  has 
a  considerable  advantage  over  kelp  in  that  it  readily  dries  and  may  be 
burnt  to  an  ash  which  has  commercial  value  as  a  source  of  potash,  while 
kelp  is  not  easily  dried  and  burnt. 

While  recovery  of  potash  from  tule  may  not  be  commercially  profit- 
able as  such,  where  there  is  no  intention  to  utilize  the  land,  it  is  quite 
possible  that  this  source  of  income  may  permit  the  recovery  of  lands 
which  could  not  otherwise  be  reclaimed  economically. 

Summary. 

1.  California  marsh  vegetation,  particularly  tule,  contains  potash  which 

may  be  somewhat  easily  obtained  and  thus  help  to  pay  cost  of 
reclaiming  the  land. 

2.  Tule  growth  along  sloughs,  etc.,  contains  potash  worth  recovering  for 

its  own  sake. 

3.  Tul^  may  be  cut  by  a  mowing  machine  and  easily  dried  and  burnt  to 

obtain  the  ash. 

4.  The  potash  is  recovered  in  the  ash  by  burning  the  dry  plants. 

5.  The  ash  may  be  used  directly  as  a  potash  fertilizer  or  from  it  may  be 

extracted  high-grade  potash  salts  by  simple,  inexpensive  methods. 

6.  The  ash  is  similar  to  kainit  as  a  source  of  potash. 

7.  Dead  or  leached  plants  have  lost  most  of  their  potash. 

8.  The  tule  plant  has  a  fertilizer  value  comparable  to  that  of  barnyard 

manure  or  Pacific  coast  kelps. 

9.  Potash  recovery  from  tule  may  never  become  a  source  of  great  wealth, 

but  it  may  be  of  considerable  local  importance  as  a  source  of  potash 
at  times  such  as  the  present  when  potash  is  very  scarce  and  costly. 


♦Bulletin  248,  page  204,  of  this  station. 


